The use of deadly force by police officers has come under critical review by law enforcement agencies, the media, and the legal profession. The authors describe procedures that have evolved and that serve to preserve the scene and witnesses' accounts, while marshaling the resources to document the circumstances. Evidence obtained through early response by specially trained homicide and physical evidence investigators is supported by a non-sworn scientist at the shooting scene. There is separate responsibility, as well as an overlap of responsibility, which must proceed concomitantly, as there are potentially both criminal and civil issues involved. Expeditious handling of the investigation tends to result in all fatal shootings being referred to a grand jury for review.